The Circle of Fifths

Why Should You Know the Circle of Fifths?

Download a Free PDF of this Tutorial – Circle of Fifths PDF

For grade 5 theory, you need to know the key signatures for every key; major and minor.

There was a time when I tried to memorise all the keys. Whilst this doesn’t take too long, it’s a bit like memorising your times tables like a script, without actually calculating it, or understanding the maths behind it. It doesn’t really improve your core understanding in maths and there is also room for error.

Knowing the circle of fifths not only gives you quick and easy access to all keys, but it also gives you a great appreciation of the relationship between different keys and therefore harmony.

This is what it looks like.

At first, that looks a little complicated, but don’t let it overwhelm you. Let’s look at it in greater detail.

Explanation of the Circle of Fifths

Moving in fifths

At it’s simplest, the circle of fifths is an arrangement of all the notes of the chromatic scale in a circle. These are designated as the capital red letters arranged around the circle above. Each subsequent pitch clockwise is 7 semitones higher (a perfect fifth) and therefore each subsequent pitch anti clockwise is 7 semitones lower.

The Keys

As we look more closely at the Circle of Fifths (CO5) above, we see there are key signatures for each of the red letters arranged around the circle too.

As we go round the circle clockwise, an interesting pattern develops:

  • If you go clockwise from C major (no sharps or flats) you arrive first to G major, which has 1x sharp = F#.
  • Proceeding further around the CO5 you get to D which has F# and C#.
  • If we go to the next key, you get to A which has F#, C# and G#.

So by going up a fifth in key, we change the key signature by 1x note, and the resulting key signature in the examples above kept the previous sharps and gained 1x sharp. In other words, the difference between the key of C major and the key of G major is only one note – F/F#. This means that they are incredibly related keys. In fact, keys that are next to each other in the C05 are the most related keys to each other.  

As we go round the circle anti clockwise, a very similar pattern develops:

  • If you go anticlockwise from C major (no sharps or flats) you get first to F major, which has 1x flat = Bb.
  • Proceeding further around the CO5 you get to the key of Bb which has Bb and Eb as flats in the key signature.
  • If we go to the next key, you get to Eb which has Bb, Eb and Ab. as flats in the key signature.

So by going down a fifth in key, we change the key signature by 1x note, and the resulting key signature in the examples above gained 1x flat. In other words, the difference between the key of C major and the key of F major is only one note – Bb. This means that they are incredibly related keys. In fact, keys that are next to each other in the C05 are the most related keys to each other.  

So, to summarise the above; the circle is arranged in fifths because this places all the keys in an order in which each key has its most related keys next to each other. C is next to F & G (a difference of only one note between C & each of them) and D is between G and A (a difference of only one note between D & each of them).

Relative minors

Looking inside the diagram above, we can see green lowercase letters. Each of the red letters has its own corresponding green one. These are the relative minors of each major key.

A relative minor is all the same notes as it’s relative major, but starting on a different note. For example, the relative minor of C is A. If you start on A and play through the musical alphabet using all the notes of C major – you are playing A minor.

Because the majors are arranged around the circle in fifths, all their relative minors are too, and their corresponding key signatures are the same.

So having a circle of fifths in front of you really helps to see all the keys, major and minor. But what if you don’t have one in front of you? Well, you memorise it!

How to memorise the Circle of Fifths

Rather than memorizing the whole of the circle of fifths, we can memorise how to create it. Let me explain what I mean.

In your ABRSM music theory exam, you have two hours to complete everything. That’s loads of time. A really beneficial thing to do at the start of the exam is to prepare a few ‘memorised’ bits on the paper provided so that you can get them out of your head and have it in front of you for easy reference. The circle of fifths is one of these things.

Here’s how you do it, although watching the video might be easier than reading all this! If this initially seems long winded, stick with it. It’s only long-winded to explain! Once you’ve got this, it’s straightforward and simple.

Step 1.

Start by drawing a circle and a C at the top and an Gb/F# (enharmonic equivalents) at the bottom. The Gb/F# will serve as your halfway orientation point so you can build the circle clockwise to Gb/F# and then anticlockwise again to Gb/F#.

This simplifies your thinking ‘on the flat side’ and ‘on the sharp side’ and prevents you making a messy circle with everything spaced out nicely on one side and squashed on the otherCircle of fiths creation, Circle of 5ths, Cycle of fifths!

Step 2.

Fill out the rest of the circle. This is done by by (unsurprisingly) starting at C and clockwise counting up in fifths. So you think to yourself, ‘what’s a fifth above C?… G’ And then you think, ‘what’s a fifth above G?… D’ etc etc. You then do this for the anticlockwise bit – i.e. the left hand side or ‘flat side’ of the circle.

Step 3.

Once you’ve filled this out, you could either fill in the relative minors or go straight on to writing the sharps and flats for each key.

For this, all you need to memorise is the key signatures for only the first two keys round the circle from C (G clockwise and F anticlockwise). G has one sharp (F#) and F has one flat (Bb). Draw these on.

Now because you’ve drawn it on blank paper, you won’t have staff lines to draw the actual sharp or flat signs on, so just list the sharps or flats for that key signature beside it. Preferably in smaller or differently coloured writing.Circle of fiths creation, Circle of 5ths, Cycle of fifths

Step 4.

There are two ways to fill out the rest of the circle. In both ways, be clear that you are:

adding a sharp to the next key signature as you go round the circle clockwise and keeping the previous sharps.
or adding a flat as you go round the circle anticlockwise and keeping the previous flats.

Technique 1.

For the ‘Sharp Side’, think up in fifths from G major.

  • From the F# in the key signature of G major, you can then think up one fifth (from F#) and you arrive at C#. C# is the next sharp that gets added when you move to the next key – D major.
  • From the C# in D major (the last # added to the key signature), go up one fifth and you get to G#. G# is the next sharp that gets added when you move to A major.
  • Repeat until you get to F# major.

For the ‘Flat Side’, think down in fifths from F major.

  • From the Bb in the key signature of F major, you can then think down one fifth and you arrive at Eb. Eb is the next flat that gets added when you move to Bb major.
  • From the Eb in Bb major (the last flat added to the key signature), go down one fifth and you get to Ab. Ab is the next flat that gets added when you move to Eb major.
  • Repeat until you get to Gb major.

Technique 2.

For the ‘Sharp Side’ you can go down a semitone from the root of each key to find the next sharp that is added. For example;

  • In G major, the sharp that is added to the key signature is F#. F# is a semitone below G.
  • In D major, the sharp that is then added to the key signature is C#. C# is a semitone below D.
  • Repeat until you get to Gb/F# major.

For the ‘Flat Side’ you can go down a tone from the root of the previous key to find the next flat that is added. For example;

  • In F major, the flat that is added to the key signature is Bb. You’ve memorised that, and so that’s where you start.
  • In Bb major, the flat that get’s added is Eb. Eb is a tone below F, the previous key on the CO5.
  • In Eb major, the flat that gets added is Ab. Ab is a tone below Eb, the previous key on the CO5.
  • Repeat until you get to Gb major.

*there’s also more patterns in the C05 which can help you remember it. It’s a little like the 9 times table in that respect – with lots of patterns. However, I’ll leave it at those more straightforward ones for now.

Circle of fiths creation, Circle of 5ths, Cycle of fifths